Okay, I dont understand this at all, please help.
NACRA 5.2 jib blocks are attached approx 1Ft inward of the hulls
NACRA 5.8 jib blocks are attached to hulls
NACRA 6.0 same as 5.8
Okay, some boats theoretically have a more open slot than others. Why is that? If the boats are wider, say an 8'6" beam, then it would seem you need to bring the jib blocks more toward the middle, but most "wide" boats have the jib blocks atached to the hulls. I am speaking of the older boats, not necessarily the Inters/tigers and such.
David Mosley
www.seacats.org
It's because beach cats with trampolines don't really have a good way of handling the jib situation. You need to be able to move the clew of the jib inboard and outboard and forward and aft in order to maintain the proper slot (or shape) for all conditions. A semicircular track, like what some A-class cats use for their main, would probably also work for a jib, but it just isn't feasible. Instead, we use tracks on the hulls, grommets in the tramp, cables across the tramp, in-and-out lines across the tramp, fore-and-aft pullers, barber haulers, and people haulers. It's a mess! If they make it simple so it comes from only one place, like a block attached through a grommet in the trampoline on each side, the jib is only going to be working right on one point of sail.
All this keeps the engineers and tinkerers busy figuring out new ways to control the jib shape. Downwind on the Hobie 18, the jib-shape controller used to be me, poised like the statue of liberty on the forward hull holding the clew out to maintain the perfect shape until I begged Rick to jibe so I could switch arms.